The weatherwise mare of Asmund in the Icelandic saga of Grettir the Strong (ca. eleventh century). Asmund believed in her weather prophecies, and when he charged his second son, Grettir, with looking after the horses, he told Grettir to be guided by Keingala, who would always return to the stable before a storm. Because Keingala persisted in remaining on the cold hillside, grazing on the scanty grass until the lad was nearly frozen with cold, Grettir determined to make her return home regardless of the weather.
One morning, before turning out the horses, Grettir tore off a long strip of her skin from withers to flank. This made the mare soon seek her stable. When Keingala did the same thing the next day, no storm impending, Asmund himself let out the horses and discovered his son's cruel trick.